The present invention relates to an ink ejection head for a printer.
Ink jet printers have been introduced into the art for use in facsimile systems, teletype systems and the like in which droplets of ink are ejected onto a copy sheet to form dots which make up characters or the like. A prior art ink ejection head to which the present invention constitutes a novel improvement comprises a pressure chamber. An electrostrictive member defines part of the wall of the pressure chamber. Ink is fed into an ink supply chamber which communicates with the pressure chamber through an ink supply orifice in such a manner that both chambers are filled with ink. An ink ejection orifice is axially aligned with the ink supply orifice and faces a copy sheet. When an electrical signal is fed to the electrostrictive member, the electrostrictive member deforms to reduce the volume of the pressure chamber. Since the ink is incompressible, an amount of ink equal to the reduction in volume of the pressure chamber is ejected through the ink ejection orifice onto the copy sheet to form a dot.
In order for the ink to be ejected straight outwardly, the orifices must be precisely axially aligned. This is difficult because the orifices must be extremely small, on the order of 10 .mu.m. Such an ink ejection head is therefore expensive to manufacture.